954 research outputs found
Inquadramento climatico e cronologico del sito Madonna degli Angeli a Tocco Casauria (Pescara)
No full textThe Chronology of Human Cultures in Europe and the Mediterranean Basin according to 14C Dating
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Sedimentation of long-lasting wind-affected volcanic plumes: the example of the 2011 rhyolitic Cordón Caulle eruption, Chile
No full textSedimentation processes and fragmentation mech- anisms during explosive volcanic eruptions can be constrained based on detailed analysis of grain-size variations of tephra deposits with distance from vent and total grain-size distribu- tion (TGSD). Grain-size studies strongly rely on deposit ex- posure and, in case of long-lasting eruptions, can be compli- cated by the intricate interplay between eruptive style, atmo- spheric conditions, particle accumulation, and deposit erosion. The 2011 Cordón Caulle eruption, Chile, represents an ideals laboratory for the study of long-lasting eruptions thanks to the good deposit accessibility in medial to distal area. All layers analyzed are mostly characterized by bimodal grain-size dis- tributions, with both the modes and the fraction of the coarse subpopulation decreasing rapidly with distance from vent and those of the fine subpopulation being mostly stable. Due to gradually changing wind direction, the two subpopulations characterizing the deposit of the first 2 days of the eruption are asymmetrically distributed with respect to the dispersal axis. The TGSD of the climactic phase is also bimodal, with the coarse subpopulation representing 90 wt% of the whole distribution. Polymodality of individual samples is related to size-selective sedimentation processes, while polymodality of the TGSD is mostly related to the complex internal texture (e.g., size and shape of vesicles) of the most abundant juvenile
Editorial responsibility: V. Manville
C. Bonadonna (*) Section des sciences de la Terre et de l’environnement, Universitè de Genève, Geneva, Switzerland e-mail: [email protected]
R. Cioni : M. Pistolesi Dipartimento di Scienze della Terra, Università di Firenze, Florence, Italy
M. Elissondo : V. Baumann Servicio Geológico Minero Argentino, Buenos Aires, Argentina
clasts. The most representative TGSD could be derived based on a combination of the Voronoi tessellation with a detailed analysis of the thinning trend of individual size categories. Finally, preferential breakage of coarse pumices on ground impact was inferred from the study of particle terminal velocity
Novel antidiabetic drugs and cardiovascular risk: Primum non nocere
No full textAbstractAimsDiabetes treatments aim at preventing undesirable metabolic effects of hyperglycemia and at preventing/reducing tissue damage, including cardiovascular (CV) events. For approval, novel diabetes drugs undergo early systematic investigation to assess CV safety. This review provides an updated analysis of the results of recent studies examining novel diabetes medications and CV outcomes.Data synthesisThe new regulatory guidelines enforce adjudication of all CV events when testing novel diabetes drugs. Endpoints of CV mortality, myocardial infarction (MI), stroke and hospitalization for heart failure (HF) were included in the most recent clinical studies on novel antihyperglycemics. These are: the incretin mimetics glucagon-like peptide 1 (GLP-1) receptor agonists (GLP1-RA), the incretin enhancers dipeptidylpeptidase-4 (DPP-4) inhibitors (DPP4-I or gliptins), and the sodium-glucose cotransporter (SGLT2) inhibitors (SGLT2-I or gliflozins). The studies ELIXA and EXAMINE, testing lixisenatide and alogliptin, respectively, revealed non-inferiority versus placebo in terms of CV safety. The SAVOR-TIMI 53 results confirmed overall CV safety of saxagliptin, but raised a warning related to the increase in the risk of hospitalization for HF in the saxagliptin group. Recently, TECOS revealed a particularly favorable CV profile for sitagliptin while EMPA-REG showed a significant CV risk reduction in empagliflozin treated subjects. Ongoing studies will provide additional data on CV safety for other GLP1-RAs, DPP4-I and SGLT2-I.ConclusionsResults of safety outcome studies focused on CV events, including HF and mortality for CV causes, are not homogeneous. A critical analysis of these studies may help cardiologists and diabetes specialists to adapt their therapeutic choices to individual patients
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